An important step in my French learning has been "conversation exchanges" with native speakers. It's a bit daunting at first, but remember that talking to native speakers is the point of learning a language in the first place!

galérer - to struggle, to slog. E.g. on a galéré dans le métro avec beaucoup trop de valises - we struggled on the tube with too many cases

on y go - something's gone very wrong with the French here...... an anglicisme of on y va - let's go/we're off/shall we go. I can't quite believe that the French use this, but I'm told that it's "in" in France....

un tas - a bunch, a heap, a pile. E.g. il y a un tas de chose à faire à Londres - there are a bunch of things to do in London